 Welcome to this lecture series on aspects of Christian philosophy module 31. So, this lecture will see the contributions of logical positivism, a very important philosophical movement in the 28th century European thought. So, in one sense we can say that 28th century is the century of logical analysis, the century of language analysis primarily. And where philosophers turn their attention to language and instead of focusing instead of trying to understand venturing into reality or world. Philosophers thought that reality or all knowledge about reality or anything for that matter is possible only through language or language there are even assertions which would even say that language is reality. The being of language for example, in the Hans Kiewer-Gadamer German philosopher calls it both continental tradition as well as the analytic Anglo-Saxon English tradition of philosophy. They both sort of took a linguistic turn, but what is so peculiar about the analytic philosophers is the kind of logical rigor they exhibited or rather they were more fascinated by this logical structure of language. And a conception of analysis, a conception of language analysis based on this logical structure or the form of language, the logical form of language which they considered is so central. And we have already examined some contributions towards this line of thought by Bertrand Russell and Wittgenstein particularly Wittgenstein's early philosophy which emphasizes on logical form on logical analysis of language. And here we come across an offshoot of these kind of an attitude in western philosophy in the turn of 20th century logical positivism. And we can see that these other thinkers like the works of Wittgenstein which I have already mentioned, tracked it as logical philosophical and also Bertrand Russell's and many other philosophers work which emphasized on the logical analysis of language tremendously influenced these people, the logical positivism. There was something which they were all trying to commonly advocate, but at the same time each one of them had their own unique approach to philosophy. And we were now trying to isolate or trying to highlight some of those important features which they all commonly advocated apart from the diverse concerns they had with regard to the conception of philosophy and the methodology of philosophy. Some of these features were so common to all of them right from you know Moorishlich to AJ Air the English the British representative of logical positivism. So, that is they were all against metaphysics, so a refutation of metaphysics constitutes so central to the concerns of logical positivism. As a consequence of this they advocate a kind of scientific conception of philosophy there is a notion of unified sciences with regard to the conception of knowledge they believe that the only knowledge that is valid is a scientific knowledge which can be ultimately analyzed the scientific knowledge can be ultimately analyzed into certain basic propositions which are statements of observation which are verifiable. So, that this conception of philosophy and the notion of unified sciences play a very important role in shaping their philosophical thinking. And again in this context it is very important to mention about verification principle and then we will see some of the limitations some of the criticism which logical positivism as a movement faced. So, these are the contents which we are going to address in this lecture, but before we really see the movement called logical positivism and its contribution. Let us see the background the situation in philosophy in 20th century like the advance in knowledge has been due to science. So, this is something which was a very influential factor in the 20th century not just in philosophy, but in all knowledge endeavors all intellectual endeavors were influenced by the developments that took place in modern science and also in technology lot of advancements science had made during this time. And we all know that the two world wars the kind of weapons people have used and ultimately the atomic bomb which again is the conception of atomic fusion all these things sort of made people to view science and its advancements from a new perspective. So, philosophers also were sort of attracted towards the kind of rigor and precision scientific method or sciences in general advocated. In speculative philosophy on the other hand. So, if this is the situation in science what is the situation in philosophy particularly the kind of speculative philosophy that was a fashion in Europe during these time. The philosophical theories of different thinkers were merely personal interpretations about reality. So, they hardly sort of you know exhibited the kind of rigor and the kind of analytic precision which was so central to scientific intervals. So, in that sense there is a clear distinction there is a clear kind of a difference between philosophical enterprises particularly the speculative philosophical enterprises and modern science. And speculative philosophical theories were not empirically verifiable they were. So, hence it is impossible to establish their truth of falsity. So, naturally people went on speculating about what should be the real nature of reality what should be what is good and how do you define goodness and how do you distinguish it from evil what is the ultimate destiny of human life meaning of human life all kinds of things philosophers have discussed elaborately extensively and quarrel with each other. But ultimately these arguments these speculations have never taken us to anywhere definite because these speculative philosophy the domain of speculative philosophy is not a domain which can be empirically verifiable observable by senses. So, that so that we can arrive at a kind of precise a kind of concise domain of knowledge they are only political or emotional reactions to the world. So, in that sense this is very interesting observation by the logical positivist that they do not reject speculative philosophy as in total they do not say that it is absolutely useless they recognize that there is a value, but the value is confined to emotional and political aspects of life. Beyond that if you try to attribute any cognitive value to the statements of speculative philosophy you are on the wrong track. None of these represent knowledge like science and applied science has tremendously changed human life. So, this is what I have just mentioned and in this context what is the job of philosophy? Philosopher does not contribute to the increase of human knowledge. So, here we can see the shadow of Wittgenstein or the influence of Wittgenstein. Wittgenstein has categorically stated in his tractators that philosophy is not a theory. Philosophy is not besides natural sciences it is different from that it is not a science at all. Only sciences can contribute to human knowledge hence since philosophy is not a science it cannot contribute to human knowledge. Earlier philosophy was the handmade of theology. So, that was the situation during earlier period where philosophy was always considered as a discipline which was very closely linked to theology in a sense even to consider it as a handmade of theology, but now with the new world where science rather has very conclusively and very convincingly has replaced religion and theology. So, philosophy here becomes a handmade of science. So, now in this context what would be the philosopher's task? We have already seen this when we have discussed Wittgenstein and Bertrand Russell to some extent because in 20th century with linguistic turn philosophy rather has a very specific task. What is it? Number one clarifying the meaning of science, meaning of terms like as Wittgenstein says philosophy is a critic of language. So, it analyzes linguistic expressions and another one is showing that or showing what words do not in terms of immediate experience. Here again you know you can see the influence of Wittgenstein is conception of elementary propositions which corresponds these elementary propositions stand in one to one relationship with reality. There is a kind of isomorphic structural isomorphic relationship between reality and propositions and language. So, philosopher's task is to analyze language and linguistic expressions and bring out this structure. Wherever language linguistic expressions fail to denote the immediate empirical experience, such expressions need to be considered as nonsensical. So, now again if you consider the background the logical positivism emerged during the post world war one period a group of intellectuals, mathematicians, scientists and philosophers even politicians were also part of this painters, artists they were all part of this movement they all began meeting in Vienna under the leadership of a philosopher Moorish Flick. They primarily discussed about the implications of recent developments in logic and in science particularly the kind of contributions made by Gottler-Fregge, Alfred North Whitehead, Bertrand Russell and more importantly Wittgenstein. They began contemplating about the possibility of a systematic reduction of human knowledge to logical and scientific foundation. So, this is one possibility which they explode whether we can reduce the reduction of human knowledge or human knowledge to a set of statements which would exhibit the logical foundations of all language. So, that was the prime concern. They emphasized materialism, empiricism, philosophical naturalism and scientific method. So, these is something which these are the common temperament shared by all these philosophers who met under the leadership of Moorish Flick in Vienna, which is famously known as the Vienna circle philosophers. And they also advocated something called a principle of verification which says that any statement that is not inherently verifiable is to be treated as nonsensical. And some of the most notable members of the Vienna circle were Moorish Flick, Hans Reichenbach, Rudolf Karnop, Herbert Fegel, Philip Frank, Kurt Grilling, Hans Han, Carl Gustav Hempel, Victor Kraft, Otto Neuroth and Frederick Weisman. And it began in 1929 formally though they have started assembling and started discussing various issues. There is a formal sort of beginning with a publication of a manifesto for logical positivism entitled the Vienna circle its scientific outlook written by Karnop, Neuroth and Han. This pamphlet gave a brief account of the philosophical position of the group and a review of the problems in the philosophy of mathematics and of physics and social sciences that they were chiefly concerned to solve. So, according to them all disciplines need to be scientific. So, that is a kind of aim they were trying to sort of pursue. And the influences as I have already mentioned, but I will briefly outline it once again. These philosophers were primarily influenced by the empiricism of David Hume and Augustine Comte, the positivist J S. Mill and Amnerius and Mac, Ennis Mac. So, these are some of the philosophers traditional thinkers. Then from the side of science of course, Einstein's theory of relativity and quantum mechanics were where tremendous influences and some of these people even attended classes on quantum mechanics and Einstein's theories. Then comes the important contribution or important influence of modern logic, formal logic, logical techniques developed by Frege, Piano and Russell and with particularly with Russell's publication of Russell's book, Principles of Mathematics and Wittgenstein's Tractators to which they developed their own unique reading. So, what it used to happen that during their meetings in the Vienna circle meetings, they used to read aloud Wittgenstein's Tractators, sentence by sentence, proposition by proposition and which is followed by long and lengthy discussions on each proposition. So, this is one book which they thoroughly analyzed and of course, their interpretations of this book was primarily influenced by Russell's introduction to Tractators, which was most in line of you know the Russell's introduction of Tractators is very interesting. He interpreted Tractators in his in the line of his philosophy, the light of his it was an interpretation from the light of Russell's own philosophy, philosophy of logical atomism. And this when this people read Tractators, they also did the same, they sort of tried to see justifications for their philosophical positions in Tractators. Now, some of the important features of logical positivism, it was uncompromising positivism, then blanket rejection of metaphysics, respect for scientific method, conviction that in so far as philosophical problems are genuine at all, they can be definitely solved by logical analysis. So, if at all there is a philosophical problem that needs to be considered as a genuine problem, then a solution could be found out with logical analysis. So, logical analysis is the key and if logical analysis leads to sort of conclusions, where you where you fail to find any definite empirical foundation for your statements, for your prepositions, then those propositions are to be treated as nonsensical. So, here comes the symbolic logic on the one hand and the humane tradition of logical empiricism on the other hand, this has influence the emergence of logical positivism. And particularly it is very interesting Hume's distinction between two kinds of statements, we have discussed this when we have discussed David Hume's philosophy in this lecture series, that Hume divides prepositions into two classes or the first one is he calls relations of ideas, where you discuss I mean for example, in mathematics where there is no corresponding reality to sentences are being postulated, where he deals with only ideas, relations of ideas and matters of fact are rearticulated as tautologies and contradictions. In their language again following Wittgenstein and Bertrand Russell, they call it tautologies and contradictions. A tautology is a statement, which is always true, which is necessarily true under all circumstances or we can say that it is a priori true. On the other hand, contradictions are those statements which are always false, they cannot be true. Similarly, factual propositions are propositions which are a posteriori, which cannot be a priori true, which the truth and falsity of those propositions need to be verified by means of experience. So, these are the two types of statements, which the logical positivist propositions, which they accept as meaningful propositions. Either propositions should be tautologies, which means they are mathematical or logical propositions, they are factual propositions, they represent matters of fact, something in the word, so that it can be either true or false. Now, sentences that are neither tautologies nor factual are not propositions, they are nonsensical, because they cannot be verified. So, from these basic insights, fundamental insights, the theory of verifiability is being derived by these thinkers. Now, the question of meaning, it is very interesting that all these philosophers of language, something which all of them commonly attempted is to develop a theory of language. Of course, Wittgenstein also does it in his tractors talks about, today we call it the picture theory of meaning, where meaning is identified in terms of correspondence with the world. So, here this I have already mentioned, according to the logical positivist, there are two types of meaningful statements, statements that are true or false by virtue of the meaning or logical form, analytic a priori and truth and falsity a certain by experience with this synthetic a posteriori. Therefore, meaning of statement is its method of verification. So, this probably is the most important, one of the most important statements, propositions of logical positivism, that meaning of a statement is its method of verification. So, a meaning is sort of understood in terms of verifiability. If a particular statement is verifiable, then it is meaningful and verifiable is again a very definite term, it means empirical observation or empirically verifiable. We know the meaning, if we know the conditions under which the statement is true or false. So, when I say there are 20 chairs in this room, if this statement if there are actually 20 chairs in this room, my statement is true. So, I should know in order to know the statement, in order to understand the statement there are 20 chairs in this room, what I should know is I should know the condition under which this statement should become true. And there might not be even one chair in this room, but still it is a meaningful statement, because I can understand its meaning, because again I know what conditions would make this statement true. And in this context they develops their rejection of metaphysics and what the logical positivist argue is that many metaphysical utterances are due to the commission of logical errors. And again enquire from what premises the metaphysicist deduce this proposition. So, ultimately concluding that, inferring that the kind of metaphysical propositions or metaphysical utterances, which philosophers have been making since time immemorial, where all due to certain logical errors, certain confusions with regard to the logic of language. This is again an original Wittgensteinian idea, which these people have modified a little bit, enquire from what a premises the metaphysicist. So, in order to know whether this proposition or any proposition for that matter, whether it is meaningful or not, we have to see from where it is being deduced. He too needs to begin, this is what the logical positivist would argue even the metaphysician would need to begin as other men do with the evidence of his senses. So, it should be seen, it should be experienced by sense organs. What valid process of reasoning can possibly lead him to the conception of transcendent reality. There is a conception of transcendent reality, which many metaphysicians advocate, but what is the basis of talking about such a transcendent reality. Are there any sense, any kind of evidence of the senses that suggests that such a reality exist. The very notion of transcendent reality suggests that senses cannot capture it, then how can you talk about it. So, all talk about such a transcendent reality is bound to be nonsensical. Again this is a quote from A. J. Air, a very prominent advocate of logical positivism from the English speaking world. And actually Air has attended some of their meetings and also introduced logical positivism to the English speaking world, because basically the developments took place in Vienna. And many of them were Germans and they were all reading Wittgenstein's original German edition of Tractatus. And in that sense, you know, Air's contribution is phenomenal, because he is the one who has introduced this new movement to the English speaking world. So, he says in this famous book, Language, Truth and Logic, which is actually a preliminary assessment on the contributions of logical positivism. So, I read a quote, the traditional disputes of philosophers are for the most part as unwarranted as they are unfruitful. The surest way to end them is to establish beyond question what should be the purpose and method of philosophical enquiry. So, you need a purpose and you also need to adopt a method, it is like science. So, in the line of science, you can see philosophy in the line of science, where science has a purpose and also a definite method. So, similarly philosophy should also need a method and also a purpose to serve. So, here a rejection of metaphysics through language analysis, here the impossibility of a transcendent metaphysics is not a matter of fact, but a matter of logic. This is something which I have already mentioned that their method is language analysis and logical analysis of language. So, if they say that the conception of transcendent reality is impossible to be advocated, because you cannot say anything about it. And the reason for that is not something which is a matter of fact, but a matter of logic. Logically they say that logically it is not possible, because the logic of language suggests that linguistic expressions when they attempt to transcend the boundaries of sense experience, they tend to be nonsensical. And here it is interesting to have a comparison with the position adopted by or the methodology adopted by Immanuel Kant, who also did something like very similar kind of an exercise, but of course, not with an emphasis on logical analysis of language, rather for Kant it was a matter of fact, the kind of metaphysics, the impossibility of a metaphysics is a matter of fact affair and hence to draw a limit to human thinking. But Wittgenstein on the other hand, as we have already seen when we have discussed the Tractatus, he says that in order to draw a limit to thinking, we should have to think both sides of the limit, which is actually not possible. Since that is not possible, the only place where we can draw the limit is language, which is nothing but which is assumed as the expression of thinking. So, that is the reason why philosophers of language adopt or take a linguistic turn. The emphasis on language, rejection of transcendent metaphysics not by merely criticizing the way in which it comes into being, but by language analysis. A criticism of the nature of the actual statements which comprise metaphysics. So, here again metaphysical statements are analyzed. The so called propositions of metaphysicians are taken for analysis and when you apply the principle of verifiability, they fail to satisfy the criteria and they are treated as nonsensical. Statements that transcend the limits of all possible sense experience have to be literal, have no literal significance though they are nonsensical. And logical positivism says that the rule which determines the literal significance of language is the criteria and the metaphysician produces sentences which fail to conform to the conditions under which alone a sentence can be literally analyzed. What is that condition under which alone as a sentence can be literally significant. Here comes the principle of verifiability and here is a quote from A. J. S. Nother book, Logical Positivism. I quote, the originality of the logical positivist lay in the making the impossibility of metaphysics depend not upon the nature of what could be known, but upon the nature of what could be said, not what could be known, but what could be said. Again their charge against the metaphysician was that he breaks the rules which any utterance must satisfy if it is to be literally significant. A. J. Ayer, Logical Positivism. All talk about God or absolute transcendental entities, substance, destiny of man, meaning of human life, goodness, etcetera are metaphysical. Again they pretend to be cognitive like the statements of metaphysicians look like other ordinary kinds of statements. See when I say God exists or God will punish you for example, God will punish you if you steal money from me. This is one statement which I would make. Again I can also make another statement which would say that your father will punish you if you steal money from me. These two statements are grammatically alike, but they are actually not. There is a fundamental difference. The first statement God will punish you if you steal money from me is a metaphysical statement or rather it is a meaningful statement. It does not signify anything, but the second statement has a definite meaning. We know what does it mean. So, the logical positivist would say that these such statements pretend to be cognitive while they are not. And again they might have emotive or poetic value, but are literal nonsense. Again as I have already pointed out they were all influenced by Wittgenstein's Tractatus. This aspect needs to be a little elaborated because Wittgenstein's Tractatus played a very important role in shaping some of the basic ideas of logical positivism. As I mentioned earlier this logical positivist whenever they used to meet they would read Tractatus allowed and each sentence each proposition was analyzed. So, particularly the notion of elementary propositions and their correspondence with fact. So, we can see that the kind of verification principle which they developed is derived from this conception, this original conception of Wittgenstein which talks about which postulates a set of propositions as elementary propositions which directly correspond to reality. So, they are sort of laid against reality. There is a kind of one to one correspondence. They are very close to reality. They sort of directly represent reality. So, postulating a set of such elementary propositions is very interesting and very important for logical positivist. So, they would say that these statements are reports of observation that touch on by reference to which all other statements were empirically verified. So, you can basically analyze your entire linguistic apparatus. You make it you subjective for logical analysis and finally, you can reach these elementary propositions. If you succeed in reaching these elementary propositions which are direct observation statements, then your statement or your propositions are considered as meaningful. So, this is the kind of derivation which the logical positivist made from Wittgenstein's original position. Again the principle of verification is derived from this. Now, let us see the verification principle a little in detail. It asserts that the meaning of a proposition is its method of verification. Meaning is the method of verification. Verification is the criterion by which we test whether ascendance expresses a genuine proposition about a matter of fact. So, if a particular statement does not express a genuine proposition which means that it does not represent a fact in the world. Actual representing and possible representing this is sort of taken care of because for them it is a method of verification which is important. I should only know whether that particular statement be verified by adopting certain methods. For instance if I say that there is no life in the moon or there is no water in the moon. This is a meaningful statement for the logical positivist. Though at present in the case of moon of course, we have now gone to moon and that may be possible, but there is make the same statement about Saturn. A planet which we have never been successful in reaching or sending things which you have already sent to Mars and other places in the in moon or as well. So, when I make a statement about there is no water in Saturn. This is a meaningful statement because this can be verified or rather I know the method by means of which I can verify it. For that I have to go to Saturn and observe it, but if I say there are two gods or there are many gods or absolute is one. These are statements where I do not know the method by means of which I can verify them. Since I do not know this method, these statements are to be treated as not verifiable and hence nonsensical. All meaningful statements including the most abstract scientific hypothesis can be ultimately analyzed to these elementary statements which stand for observable events. So, this is what the emphasis on logical analysis would yield to because you can every statement there are certain very abstract scientific theories which cannot be directly verified, but yet they are meaningful because they can be analyzed. They can be analyzed into simple elementary propositions which correspond to reality which are directly verifiable. So, this fact of logical analysis would reveal that even such abstract statement which do not apparently stand directly in correspondence with reality are meaningful. In AJ Air I quote, a sentence is factually significant to any given person if and only if he knows how to verify the proposition which it purports to express. That is if he knows what observations would lead him under certain conditions to accept the proposition as being true or reject it as being false. And here when you talk about verification actually this is something which AJ Air has enumerated. He would say that there are basically four types of verification, there is practical verification which is practical. I can verify it there are 20 chairs in this classroom is something which I can verify by observation right now, but there are certain statements which are not so easily and verifiable in this way in the practical sense of the term, but they are in principle we can verify them. We know that if certain conditions are met I can verify them then there is a strong verification and weak verification we will very briefly see what are they. So, observations are possible in practice in order to confirm whether a proposition is true or false. In practice it is possible that I can see I can count whether there are 20 chairs here or not in practice I can do that. On the other hand verifiable in principle means propositions for which we do not have a practical means of verification that may still be meaningful if we can theoretically verify them. Then comes the strong verification if and only if its truth could be conclusively established in experience. Difficult to hold on many occasions like all men are mortal for example, bodies expand when heated all these are all bodies expand when heated for instance or all men are mortal where there is a reference to all these are statements which we all know are sort of verifiable they are meaningful statements, but at the same time if you apply the criteria of strong verifiability which means that statement should be conclusively established in experience. If make such statements directly stand they may not pass the test of this criteria the strong verifiability. Such general propositions of low are designed to cover an infinite number of cases hence cannot be conclusively verified for example, when I say all men are mortal I include under this all men every human being who are born died and yet to be born. And weak verification is if it is possible for experience to render it probable there is no strong conclusive verifiability asserted here the question is would any observations be relevant to the determination of its truth or falsehood. If not the statement under consideration is not so it is very modest that is the only requirement it has to meet. So, what is weak sense of verifiability little bit elaboration by A. J. Air he is adds a genuine factual proposition need not be equivalent to an experiential proposition or any finite number of experiential propositions, but simply that some experiential proposition can be deduced from it in conjunction with certain other premises without being deducible from those other premises alone. But as like all of us would have by now understood some of the important points which the logical positivist were trying to assert they started out with the concept of I mean their fundamental purpose is the rejection of metaphysics the negative side and on the positive side to arrive at a scientific conception of knowledge how a universal science is possible. So, that all knowledge is scientific there is no confusion. So, that is the kind of purpose with which the logical positivist actually began their enterprises and then in that process they thought that it is important to reject refute metaphysics and they adopted the methodology of language analysis and also the principle of verifiability there are different ways in which this is understood this is what we have seen. But this principle of verifiability has got certain difficulties for example, we can say that you know as we have seen they depend on a lot on the availability on the possibility of elementary propositions. The elementary propositions which stand directly in touch with reality they are directly in contact with reality. So, but the question is are elementary statements infallible you say that they are directly in touch with reality, but to what extent they are infallible you are you probably are mistaken then again do they refer to the private sensations of the speaker or to the public physical events again like when I say the temperature of this room is 28 degrees centigrade. This is something which a statement which I make about the world and whether this statement is about a private sensation or a public physical event are they mere records of the subjects immediate experience. How can we overcome the threat of solipsism if that is the case again the transition from the subjects private experience to the experiences of others and to the public world is always a problematic thing and again the principle of verification is not itself verifiable. So, logical positive it seems to be assuming the validity of the verifiability principle. Now, comes the notion of unified sciences as I already mentioned the logical positive is we are trying to develop notion of unified science where by developing a common language in which all scientific propositions can be expressed. There again the approaches language analysis the approach of language analysis they thought that they can actually create a language a common language which all scientific propositions can express through that language. Any of these logical positivist actually attempted at developing such languages artificial language common language. See for example, Karnamp has endeavored in doing something very similar to this all knowledge can be codified in a single standard language of science which ultimately show the one to one correspondence between language and reality. Then again carry out through several reductions or explanations of the terms to more fundamental expressions that stand for observation. So, this is analysis though you can have reductions or explanations of the terms to more fundamental expressions that stand directly in correspondence with reality. Actually it is not right to say that it is correspondence with reality it is something which we observe again the emphasis is on observation. So, the problem is that whether it is an observation is private or not is a question like what we have raised just before this. Now, scientific theory is also a kind of as I already mentioned a very abstract network of knowledge an axiomatic system not directly verifiable because it is an abstract formal system, but empirical interpretation of these abstract system is possible by means of those statements that establish a correlation between real objects and the abstract concepts. So, there is something called rules of correspondence. So, we can analyze these abstract theoretical formal state system into empirical statements and finally, two elementary statements which directly are in touch with reality. And scientific theory needs such rules of correspondence for empirical interpretation and verification. We can see the summary of scientific theory how scientific theory theories are constituted. So, you can see that you know there is there are logical terms out of which science would have certain logical statements and only logical terms would be there. Then you have observational terms where out of which you make observational statements which include observational and logical terms. And then you have theoretical terms where the theoretical statements which include logical terms and observational and logical terms which include both. So, the pure theoretical statements and mixed theoretical statements out of which the theoretical statements are composed of. So, this is the picture of scientific theory, where again ultimately this can be reduced into statements, which directly corresponds to reality. All sciences share a common language. So, this seems to be the most important, most fundamental assumption of this notion of unified science. All scientific terms could be restated as or reduced to a set of basic statements or protocol sentences describing immediate experience of perception. So, they are called protocol sentences. They directly stand in correspondence with reality. Reduction of all scientific terms to terms of physics is possible that is according to the logical positivist and the procedures for testing statements in the various sciences are basically the same. That is analysis. There is a logical analysis of language based on the principle of verifiability. And in this context, according to the logical positivist the primary function of philosophy is not to propose basic principles of knowledge. Here we can see the legacy of Wittgenstein. It was Wittgenstein who said that philosophy is not a theory. Philosophy will never give you knowledge. So, again not to construct a detective system of meaningful propositions by offering the consequences of basic principles of knowledge as a complete picture of reality. So, that is not the purpose of philosophy at all. And philosophy in that sense has a very modest purpose to serve. What is it? Philosophy clarifies the logical relations of empirical propositions. So, it is a logical analysis ultimately what philosophy does with which clarifies philosophically clarifies the logical relations of empirical propositions. This is what the overall philosophical position of logical positivism is all about. So, we can see that the important points to be remembered are number one. They were influenced by the development in sciences and they were trying to develop a scientific method, a scientific philosophy, a scientific conception of philosophy. And in that connection a unified science where all knowledge can be reduced to certain propositions which are directly observable. Number two rejection of metaphysics and number three principle of verifiability. When we try to make a final assessment about logical positivism, we can see that the impact of scientific developments in philosophy in their philosophical principles and theories were quite evident. Philosophy of logical analysis. So, you can see that the emphasis on logical analysis which distinguishes the logical positivist movement from other philosophical movements. Despite all their limitations, they were they were as quite assertive about the logical rigor which needs to be adopted when you philosophize. The attempt to make philosophy scientific. This is again a very unique attempt which was done by these thinkers and the question is whether it is a failed attempt or not. Actually, this is an interesting question which if you try to see whether logical positivism was a failure or not. So, it is a little inappropriate to really pause such a question whether a philosophy is a failure or a success. A philosophy as these people themselves claim is not a scientific theory. If it is a scientific theory, then you can say whether it has succeeded in attaining certain goals or making certain products or whatever. The philosophy is not a theory about which we can say that it was a successful theory or not, but rather they were sort of trying to point out that there are certain things which are to be treated as important and the criteria for understanding knowledge. In that sense, their philosophy is a very important moment and the most important contribution of these philosophy is to logical analysis of language and the kind of as I already mentioned logical rigor they have exhibited when they philosophize. That is quite remarkable and in that course, many of the old philosophical problems were exposed, but overall there are hardly any supporters for these philosophical moment in today's world, though they themselves understood the limitations of their philosophy and try to overcome this. We have already seen how AJ Air had formulated the principle of verifiability in different ways and Air also discusses the principle of falsifiability proposed by Karl Popper. It was a kind of response to the limitations and failures of the principle of verifiability, but ultimately philosophy goes on and the philosophy of language, the kind of the brand of philosophy these people were trying to advocate is not really relevant today in the sense that there are hardly any philosopher who would advocate this philosophical position in today's world, but the historical importance of this moment is no doubt extremely important. We will wind up this lecture now. Thank you.